These are Neapolitan fried ravioli, for want of a better name, and are an indispensable part of Frienno e Magnanno, the classic Neapolitan fritto misto. They'll also work quite nicely as antipasti, or as a side dish, and you may find yourself making them as snack food.
2 1/2 cups (250 g) flour
A walnut-size chunk of rendered lard or unsalted butter
Make the pasta, using just enough water to form the dough, and let it rest, covered,
for an hour.
Put the ricotta through a strainer, then combine it with the eggs and parsley,
grate some pepper into it, and beat well, until the mixture is creamy.
Dice the mozzarella and provolone, and finely dice the prosciutto. Combine the
ingredients with the ricotta mixture; the filling should be firm but creamy.
Roll the pasta out dime thin, keeping the sheet rectangular if possible. Lay
out a row of small walnut-size chunks of filling an inch from the straightest edge
of the sheet, separating them about 2 1/2 inches apart. Fold the sheet over the
blobs and tamp it down well all around them so it sticks, then use the edge of a
glass or a serrated pasta wheel to cut the panzerotti free in the shape of a half
moon. Put the completed panzerotti on a lightly floured surface and repeat the operation;
you can either reform the cuttings into a ball and roll them out anew or twist them
into fanciful shapes and fry them too when you fry the panzerotti.
When you are done making the panzerotti heat the oil and fry them, a few at a
time, until golden brown.
Drain them well on absorbent paper and serve at once.